Another reason to love your body! Breast milk is perfect baby food. You can never buy this liquid gold.
Read more about how breastfeeding benefits sleep and reducing colic in this study: Breastfeeding may improve nocturnal sleep and reduce infantile colic: potential role of breast milk melatonin.
Their conclusion: Exclusive breastfeeding is associated with reduced irritability/colic and a tendency toward longer nocturnal sleep. Breast milk (nocturnal) consists of substantial melatonin levels, whereas artificial formulas do not. We speculate that melatonin which is supplied to the infant via breast milk plays a role in improving sleep and reducing colic in breast-fed infants compared to formula-fed ones.